rtcm/
lib.rs

1//! # rtcm
2//!
3//! An example project.
4
5// Extra lints you may or may not want
6#![deny(
7    missing_copy_implementations,
8    missing_debug_implementations,
9    missing_docs,
10    trivial_casts,
11    trivial_numeric_casts,
12    unsafe_code,
13    unstable_features,
14    unused_import_braces,
15    unused_qualifications
16)]
17
18use std::fmt;
19
20/// A specialized [`Result`] type for pointless operations.
21pub type Result<T> = std::result::Result<T, NotFourError>;
22
23/// The number wasn't four
24#[derive(Debug, Clone, Copy)]
25pub enum NotFourError {
26    /// Not four
27    Close,
28
29    /// Sort of four
30    NotClose,
31}
32
33impl std::fmt::Display for NotFourError {
34    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
35        match self {
36            NotFourError::Close => write!(f, "it's pretty close to four"),
37            NotFourError::NotClose => write!(f, "it's definitely not four"),
38        }
39    }
40}
41
42impl std::error::Error for NotFourError {}
43
44/// Do work.
45///
46/// ```
47/// let result = rtcm::do_work(4).unwrap();
48/// assert_eq!(result, "it's four");
49/// ```
50pub fn do_work(input: usize) -> Result<&'static str> {
51    match input {
52        n if n == four() => Ok("it's four"),
53        3..=5 => Err(NotFourError::Close),
54        _ => Err(NotFourError::NotClose),
55    }
56}
57
58fn four() -> usize {
59    2 + 2
60}
61
62#[cfg(test)]
63mod tests {
64    use super::*;
65
66    #[test]
67    fn it_works_private() {
68        assert_eq!(four(), 4);
69    }
70}
rtcm/lib.rs

rtcm/
lib.rs
